XP keeps rebooting, don't know why

After a complete system crash, I have reinstalled everything and now I keep running into the same problem that caused the crash in the first place. What happens is that about 30 seconds after start up the system reboots. It does not happen all the time but about every fourth or fifth time. These reboots got more frequent before and eventually the whole system went down.

I have a suspicion that NIS 2005 is the cause of this, as the reboots started happening after I installed it. And upon the reinstall (I've installed it again after I reformated and reinstalled XP) even though I have disabled NIS 2005 from starting itself up at start up, I still have the same problem.

When the system reboots, I get a MS error report and this message;
C:\DOCUME~1\TRG\LOCALS~1|Temp\WER8d24.dir00\Mini071506-01.dmp
C:\DOCUME~1\TRG\LOCALS~1|Temp\WER8d24.dir00\sysdata.xml

I hope someone can shed some light on this for me.
Thanks in advance

Halder

Check Event Viewer for error messages

Are you using an older XP version? Service pack 1 or 2?I remember a while back there was some virus (dont remember if it was a worm or virus) that would cause your system to keep rebooting 30 seconds after it started up.It was a real pain to get rid of.Perhaps someone here remembers what im talking about?I forgot the name because it was ages ago.

Thanks Rik, by checking the Event viewer I was able to get a little bit more
detail. I am going to try setting the IPSEC Service, in Services to manual
and see if this fixes the problem. I read online about others with similar
problems and this was caused by IPSEC Services. Apparently, XP firewall and other Security firewalls running at the same time may cause some problems, such as mystery reboots when this service is enabled.

Well there's only one way to find out.

I'll let you know what happens.

As to this being a worm/virus, I don't think so as Spybot and NIS have not
reported anything after scanning

Thanks
halder